<!DOCTYPE html>
<html lang="en">

<head>
	<meta charset="UTF-8">
	<meta http-equiv="X-UA-Compatible" content="IE=edge">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<title>Document</title>
</head>

<body>
	<script>
		var length = 10;
		function fn() {
			console.log(this.length)
		}

		fn()
		let person = {
			length: 5,
			say: function () {
				fn();
				console.log(this);
				(() => {
					console.log(this.length)
				})();
				arguments[0]()
				console.log(arguments)
			}
		}

		person.say(fn)
	</script>
</body>

</html>